Interlock for elevator doors



May 6, 1941. J. c. wlLMoT ITERLOCK FOR ELEVATOR DOORS 2 Shets-Sheet l Filled May 20, 1957 J. C. WILMOT INTERLOCK FOR ELEVATOR DOORS Filed May 20, 1937 2 Sheets-Sheet 2 raf? Patented May 6, 1941 Unirse srarss eerst' erica 2,240,820 INTERLGCK FOR ELEVATOR DOORS John C. Wilmot, Chicago, Ill. Application May 20, 1937, Serial No. 143,647

6 Claims.

This invention relates to interlocks for elevator doors and the like.

Gne o the main objects of the invention is to provide an interlock mechanism in which, when the latch means for locking the door closed is released, the motor circuit for the elevator car is opened and the car put out of service as long as the latch means remains released.

It is also an object of my invention to provide an interlock mechanism in which the latch means for the door is positively maintained in engagement with the interlock mechanism as long as the door is closed, and cannot be released to permit opening of the door without opening the motor circuit for the elevator car as has heretofore been possible by springing the door sections apart, or the lower door section downwardly.

It is another object of my invention to provide an interlock mechanism of this sort, with means operated by the opening movement of the door for positively preventing closing of the car circuit after this circuit has been opened by release of the latch means for the door and until the door is closed and the latch means returned to locking Y position.

Another object is to provide means for locking the door latch in locking position and the car circuit closed when the elevator car is away from the iioor, and for releasing the door latch and the means for opening the car circuit when the car is at the oor.

A further object is to provide a heavy duty interlock which cannot be circumvented and which is suitable for use where the strictest safety rulings prevail; also, a pensive construction, and which operates positively and effectively under all conditions.

A further object is to provide for positively breaking and making Contact means in any circuit of any elevator or the like by closing and opening of the door and, at the same time, for preventing closing of the contact means when the door is open and until the door is moved to closed position.

A further object is the provision of generally improved means for locking the door sections of a plural section door together in the closed position thereof, and improved latch retainer means for holding `the latch bars out of engagement with the door stop in opening and closing the door, so as to avoid friction or contact of the latch bars with the stops as the door is opened and closed, and any wear or other undesirable results which might be produced thereby.

Further objects and advantages of the invendevice of simple and inextion will be apparent from the following detailed description, taken in connection with the accompanying drawings in which:

Figure 1 is a fragmentary elevation of a door showing an embodiment of the present invention in connection therewith;

Figure 2 is a fragmentary side elevation showing the interlock mechanism and the control shoe on the elevator car for cooperation therewith;

Figure 3 is a fragmentary elevation of the interlock mechanism on a slightly enlarged scale, with the cover for the box or housing for the interlock mechanism removed;

Figure 4 is a View similar to Figure 3, showing the postions of the parts of the interlock mechanism when the latch bar is withdrawn to released position in opening the door, and the manner in which the locking means is projected to prevent closing of the car circuit after it has been opened by release of the latch means for the door and until the door is closed and the latch means returned to locking position;

Figure 5 is a vertical sectional View taken on the line 5-5 of Figure 4;

Figure 6 is a fragmentary detail plan view of the end of the latch bar; and

Figure 7 is a fragmentary horizontal section through the door guide and adjacent jam means showing the doorway and, generally, the positioning of the door and interlock mechanism.

In the embodiment of the invention selected for illustration, the elevator car 5 (Figure 7) operates vertically in the shaft '6, and 'l designates the wall between said shaft and the respective floors, said wall 'l having an opening or doorway 8, one for each floor, along the jambs or sides of which are secured suitable vertical guides 9.

The door shown comprises an upper section l0 and a lower section I I, the lower and upper edges I2 and I3, respectively, of which meet across the doorway 8 when the door is closed. The door sections IIJ and II move vertically away from each other in opening, as well understood in the art.

The latch mechanism comprises a latch plate or disc 20 pivoted centrally at 2ly to the lower door section l I just below the frame along the upper edge thereof. Secured to the disc 20 and projecting radially therefrom is a handle 22, by means of which the disc 20 may be turned or rotated about its pivot 2|. Pivoted to the disc or plate 20 at 23 and 24, respectively, are two latch arms or latch bars 25 and- 26. The latch bars 25 `and 26 extend generally horizontally toward opposite sides of the door, and their free ends are adapted to project through the frames along the opposite sides oi the door to overlie stops 23 secured to the vertical guide members 5. A spring 35 normally maintains the handle 22 in substantially the position shown, and the latch bars 25 and 26 in their positions projected from the oppositesides of the lower door section When the door sections or panels I and I are brought together, the latch bars and 26 are sprung into place over the stops 28, thereby loching the door closed. Opening of the door necessitates withdrawal of the latch bars 25 and 26 from cooperation with the stops 28. This is accomplished by rotating the disc 29 by means of the handle 22 in a clockwise direction (Figure 1), the pivoting of the latch bars to the disc or plate 25 at 23 and 25 being off-'center or eccentrically disposed with respect to the pivot 2|. The latch as thus described is a typical side locking latch. s

Its details may be varied to suit the requirements cf different installations.

The elevator car 5 is driven or operated in the present instance by `an electric motor shown diagrammatically at S5 in Figure 3. The particular disposition of the motor and the driving connections between this motor and the elevator car 5 form no part of the present invention, and they have, therefore, been omitted. The motor circuit includes conductors 56 which lead into a box or housing 5l mounted, for example, on the guide 9 adjacent the outer end of the latch bar 25. While I have shown a left-hand interlock, i. e. a device in which the interlock mechanism is at the lefthand side of the door as viewed in Figure 1, it it to be understood that the interlock mechanism may be right-hand or left-bandas desired. The conductors 35 may be enclosed in a ilexible or other suitable conduit 38 secured to the box or housing 37. Within the box 31 the ends of the conductors 35, from which the insulation is removed, have electrical connection with contacts or terminal posts mand 4| mounted upon an insulating block 132.

A bridging contact 43, held yieldingly in projected position by spring means lid, is mounted upon an insulating block 45, which block is mounted upon an arm 46 pivoted at G1 within the box. 3l. The arm 55 is preferably counterweighted at 55, and when the latch springs into locked position, the bridging contact 43 is driven firmly against the contacts or terminal posts 49 and 4| with a wiping motion, making a positive bridging connection between the terminals, and thereby completing the motor circuit.

The end of the latch bar 25 is turned at right angles at 59 as shown in Figure 6, to engage in a notch 5i in the arm 55, fand thereby between the lugs 52 and 53, constituting an integral part K of the arm 45. The notch 5| and lug 53 are of relatively great length, which, with the turning in of the end 55 of the latch bar 25, provides relatively great vertical extent of engagement between these parts when the latch bar is in locked position. This relatively great vertical extent of .x1

engagement with the stop 25 disposed-as shown positively prevents springing the door sections l5 and il apart, or the lower door section downwardly suiliciently to release the latch bar 25 its engagement with the arm 45. The latch bar therefore cannot be released, notwithstanding the usual setting of the buildings with which these devices are employed, without swinging the arm e6 with it and the bridging contact 53 out, of. engagement with the contacts lll and 4| to open the circuit for the elevator car, and thereby prevent operation of such car when the latch bar 25 is so released.

To prevent swinging of the arm 45 to engage the contact 43 with the contacts 49 and 4| after the circuit has been opened by withdrawal of the latch bar and without closing the door and springing the latch bar to locked position, the upper end of a vertical rod 55 constitutes a locking bolt which is positioned upon opening of the door directly in the path of swinging movement of the lug 52 in a clockwise direction, and thereby `positively blocks movement of the arm 56 in a direction to engage the bridging contact with the contacts 5 and 5|. The rod 55 extends vertically along the adjacent guide 9, and is connected at its lower end at 55 to a connecting link 51, which link 5l is pivoted at 58 to an arm 59 for vertical actuation of the rod 55 by swinging movement of said arm 59. The arm 59 is in turn actuated by an arm 55 which, in the closed position of the door, underlies the lower edge of the lower door section or a lateral extension thereof, as shown in full lines in Figure 1. As soon as the latch bars 25 and 26 are released and the lower door section moved downwardly, it swings the arm 55 about the pivot 5| to the position shown in dotted lines, projecting the rod 55 upwardly and its upper end through the opening 52 in the bottom of the box 3l to locking position as shown in Figure 4.

The arms 59 and 65 may be fixed to a short shaft or pin mounted in a bracket 63 xed upon the guide 9, or the arms 59 and 65 may constitute integrally connected arms of a bell-crank lever swingable upon a pin or shaft constituting the pivot 5l. The connection at 55 is preferably a threaded connection, whereby the action of the rod 55 may be adjusted.

A supplementary arm 55 is provided for use Where suitable or desired, and particularly Where the elevator car has a push button control, although the use of this arm is not limited to cars provided with such controls. The arm 55 is swingable about the axis of a shaft 65, and has a hub El provided with clutch teeth engaging at 68 clutch teeth on a collar 59 xed upon the shaft 55. The toothed engagement at 68 permits adof the arm l5 to stop and thereby lock the arm 46 against counterclockwise swinging movement, thereby locking sthe bridging contact i3 in engagement with the contacts 49 and 4| and the latch bar 25 against withdrawal from locking position.

The upper end of the arm 55 has a roller 76 which cooperates with a shoe member 'i6' carried by the elevator carV 5. When the car is at the iloor, the shoe by its engagement with the roller l5, swings the arm 55 from the position shown in dotted lines to the position shown in hill lines in Figure 2. This movement of the arm. 55 turns the shaft 55 in a direction which swings the upper end of the detent 'i0 out of the plane of swinging movement of the arm i5 and to the position shown in full lines in Figure 2. This releases the arm i5 so that the latch bar 25 may be withdrawn to released position to open the door, and simultaneously the motor circuit,

the rod 55 being simultaneously projected upwardly to lock the motor circuit open uniti] the door is closed and the latch bar snapped to locking position.

The rod 55 may move downwardly by gravity to release the upper end of the same from locking position when the door is closed. It is to be understood, however, that this releasing movement of the rod 55 may be augmented or accomplished by spring means, or the rod may be connected to the door in a manner positively to withdraw the rod to released position when the door is closed, as well as positively to project same to locking'position by the opening movement of the door.

In the illustrated embodiment of the invention, the shoe i is carried by an angle member 80 which is secured by bolts 8| and nuts having threaded engagement therewith to an angle member 82 secured, in turn, to the elevator car 5. The openings in the angle members 80 and 82. through which the shanks of the bolts 8| extend, are elongated as shown at 83 to permit adjustment of #the shoe i5 toward and away from the door 5 for the purpose of adjusting the action imparted to the arm 65 by the shoe.

'Ihe box 3l has a hub part 84 which is Dre-ferably provided with a stop shoulder 85, and the collar 69 has a stop lug 86 which engages the shoulder 85 to limit the swinging movement of the arm B5 under the action of the shoe I6. The box 3l is preferably provided with a suitable cover 88.

From the foregoing, it will 'now be apparent that as the upper and lower panels of the doo-r are brought together, the angular end of the latch har 25 moves up along the inclined surface 00 of the stop 28 and into the notch 5| in the arm 46. The latch bar then springs into place over the stop 28, and by engagement with the lug 52, swings the arm i6 in a clockwise direction, driving the bridging contact 43 firmly against the contacts o-r terminal posts 40 and 4| to close the motor circuit for the elevator car. The car may then be moved in the ordinary manner. As the latch bar is withdrawn to released position to open :the door, the engagement of the hooked or angular end 5i] with the lug 53 positively pulls the bridging contact 43 away from the contacts or terminal posts 40 and 4| and puts the car entirely out of service as long as the latch remains open. At the same time, immediately the lower door section is moved downwardly, it operates through the connections described to project :the rod 55 upwardly into locking position as shown in Figure 4. When in this position, the upper end of the rod 55 positively prevents the contact 43 being moved into bridging engagement with contacts 40 and 4| until the door has been closed and the latch mechanism snapped into locking engagement. v

When the arm 65 is employed, this arm operates when the car is at the floor to release the latch mechanism so that the latch means for the. door may be released and the motor circuit for the car opened. When the car is away from the floor, the detent or dog member 10 operates to lock the latch means for the door in locked position and the motor circuit for the elevator car closed.

For the purpose of locking the door sections l0 and together in closed position thereof, a member |00 having a depending hooked part |0| is secured to the bo'ttom of the upper door section |0 as shown in Figure 1.

As the door is closed the hooked part 0| moves down through an opening |02 in the top flange I3 of the lower door section to substantially the position shown. The latch bar 25 has a cooperating hooked member |03 secured thereto. As the door reaches closed position and the latch bar 25 is projected into position over the stop 28, this projection of the latch bar moves the hooked mem- -ber |03 into engagement with the hooked part |0| to lock the door sections |0 and together. When the latch bar 25 is withdrawn, it moves the hooked member |03 out of engagement with the hooked part |0| so that the door may be opened.

A latch retainer arm |05 is preferably pivoted at |06 to a bracket |01 secured to the top flange I3 of the lower door section. One end |08 of the arm |05 is positioned in the path of movement of the hooked part |0| to be engaged thereby and lifted, at its opposite end, about the pivot |06 to the position shown when the door is closed. Upon release of the hooked member |03 from the hooked part |0| and withdrawal of the latch bar 25 to open the door, the downturned detent |09 on the arm |05 drops, by the greater weight of the arm |05 on the right hand side of the pivot |06 than on the left hand side of said pivot, into a notch ||0 in the latch bar 25 and holds the latch bar in retracted position.

This holds the outer end of the latch bar 25 out of engagement with the door stop in opening and closing the door so as to avoid friction or contact of the latch bar with the stop as the dooris opened and closed, and any wear or other undesirable results which might be produced thereby. The use of one latch retainer arm |05 in connection with one latch bar 25, as described, serves also to hold the other latch bar 26 in retracted position through the disc 20.

A bumper member |2 is preferably secured to the bottom of the upper door section, or to the top of the lower door section, for cooperation with the other door section in bringing the sections to closed position.

For power operation of the door, a fusible block E25 may be mounted on the lower door section. A nut |26 is molded or held against turning in this block, and a screw |21 passes loosely through the block |25 and has threaded engagement with the nut |26. The lower end of the screw |27 has a head |28 against which the handle 22 engages when the latch bars 25 are projected in the normal operation of the door. By engaging the screw head |28 with a suitable tool, the screw is threaded downwardly from the block |25, and the engagement of the head of the screw |27 swings the handle 22 in a clockwise direction (Figure l.) to retract and lock the latch bars 25 and 26 in retracted position where power operation is employed for the door. In case of a fire, the excessive temperature fuses the block |25 and releases the blocking out operation of the screw |2l so that the door may be used with the interlock mechanism as herein described,

I do not intend to be limited to the precise details shown or described.

I claim:

1. In combination, a movable carrier, a drive motor therefor, a circuit for said motor, a closure, latch means for said closure, means for opening said circuit when said latch means is released and for closing said circuit when said latch means is engaged, and means for preventing closing of said circuit when said closure is open and until said closure is moved to closed position, said last means comprising a locking bolt and a pivoted arm underlying the bottom of the closure when said closure is closed, said arm being swingable and connected to actuate said locking bolt vertically by opening movement of said closure.

2. In combination, a movable carrier, a drive motor therefor, a circuit for said motor, contact means in said circuit, a pivoted arm having contact means movable into and out of engagement with said rst contact means to close and open the motor circuit by swinging movement of said arm, a vertically movable closure member, a stop member, a latch member carried by said closure member, means for snapping said latch member intoY locking engagement with said stop member when said closure member is closed, said latch member having interlocking engagement with said pivoted arm when in locking position, and a member restrained against lateral movement and shiftable vertically along the side of. said closure member and actuated by the closure member for locking said pivoted arm against swinging movement to closed circuit position when the closure member is opened and until said closure member is moved to closed poition. Y

3. In combination, a movable carrier, a drive motor therefor, a circuit for said motor, contact means in sai-d circuit, a pivoted arm having contact means movable into and out of engagement with said first contact means to close and open the motor circuit by swinging movement of said arm, a vertically movable closure member, a stop member, Ia latch member carried by said closure member, means for snapping said latch member into locking engagement with said stop member when said closure member is closed, said latch member having interlocking engagement with said pivoted arm when in locking position, and means for lockingV said pivoted arm against swinging movement to closed circuit position when the closure member is opened and until said closure member is moved to closed position, said last means comprising a locking bolt restrained against iateral movement and actuated vertically1 by opening movement of said closure member.

4. In combinati-on, a movable carrier, a drive motor therefor, a circuit for said motor, contact means in said circuit, a pivoted arm having Contact means movable into and out of engagement with said lirst contact means to close and open the motor circuit by swinging movement of said arm, a vertically movable closure member, a stop member, a latch member carried by said closure member, means for snappingsaid latch member into locking engagement with said stop `member when said closure member is closed,

said latch member having interlocking engagement with said pivoted arm when in locking position, and means for locking said pivoted arm against swinging movement to closed circuit position When the closure member is openedand until said closure member is moved to closed position, said last means comprising a locking bolt and a pivoted arm underlying the bottom of the closure member when said closure member is in closed position, said arm being swingable and connected to actuate said locking bolt vertically by opening movement of said closure member.

5. In combination, an elevator shaft having a doorway leading to a floor, an elevator car operable in said shaft, la drive motor there-for, a circuit for said motor, contact means in said circuit, a pivoted arm having contact means movable into and out of engagement with said rst contact means to close and open the motor circuit by swinging movement of said arm, a vertically movable closure member, a stop member,

a latch member carried by said closure member and adapted :to be projected to overlie said stop member to lock said closure member in closed position, said latch member having interlocking engagement with a notch in said pivoted arm when said closure member is in closed position, a member restrained against lateral movement and shiftable vertically along the side of said closure member land actuated by the opening of said closure member for locking said pivoted arm against swinging movement to closed circuit position,and means for locking said arm in closed circuit position and in interlocking engagement with said latch member when the elevator car is away from the floor and for releasing said pivoted arm when the car is at the floor.

6. In combination, an elevator shaft having a doorway leading to a iioor, an elevator car operable in said shaft, a drive motor therefor, a circuit for said motor, contact means in said circuit, a pivoted arm having contact means movable into and out of engagement with said rst contact means to close and open the motor circuit by swinging movement of said arm, a vertically movable closure member, a stop member, a latch member carried by said closure member and adapted to ibe projected to overlie said stop member to lock said closure member in closed position, said latch member having interlocking engagement with a notch in said pivoted arm when said closure member is in closed position, a locking bolt restrained against lateral movement and shiftable vertically into the path of swinging movement of said pivoted arm by opening movement ci said closure member to lock said arm against movement 'to closed circuit position when the door is open, a detent engageable with said arm to lock the same against movement to open circuit and latch released position when the elevator car is away from the iioor, and

means on said car for releasing said detent when the car is at the door.

JOHN C. WILMOT. 

